a) Field of the Invention
The invention is directed to a connection of structural component parts in adjusting devices for seats, in particular for motor vehicle seats, in which the structural component parts to be rigidly connected with one another are welded in their connecting region.
b) Background Art
The prior art known from DE 33 03 069 C2 discloses a vehicle seat in which the sides or cheeks of the seat part and those of the backrest frame are connected with one another with reinforcing plates and articulated parts by means of rivets. At least the cheeks of the backrest frame have beads in the region of their connection flanges at the articulated part and at the reinforcing plate, which beads abut at these structural component parts and are welded thereto. As a rule, open arc welding is used for this welding process and is carried out by means of a metal electrode. It is well known that high temperatures occur in the structural component parts to be welded and can lead to stresses and warping in thin-walled structural component parts so that it may be necessary to subject the structural component parts to heat treatment to relieve stresses.
A motor vehicle seat with seat rails arranged on both longitudinal sides of the seat is known from the prior art in DE 32 46 564 A1. The running rails of the seat rails are formed by two section plates which are joined to form a rail having an approximately T-shaped cross section. One section plate forms a support section and the other section plate forms a retaining section, these two section plates being connected with one another by spot welding to form the T-shaped rail. Further, in order to connect the articulated parts to the backrest frame on the one hand and to the running rail on the other hand, these structural component parts are connected with one another by spot welding. As was mentioned above with respect to arc welding, spot welding also leads to an intensive heating of the structural component parts to be connected with one another so that stresses result from the welding process after the connected structural component parts have cooled. These stresses reduce the stability of such structural component parts under load, particularly in a crash situation.